As electric currents flowing through electronic components used in automobiles and industrial machines increase, the operating temperatures of the semiconductors used inside these electronic components tend to increase. Therefore, there is a strong demand for bonding materials that can resist such a high-temperature environment. Conventionally, lead-containing solder that can maintain its strength at high temperatures has been used. However, with the recent trend of reducing the amount of lead used, there is a strong demand to provide a bonding method suitable for such a requirement.
As a candidate of the bonding method that can meet the above requirements, a bonding method using silver nanoparticles is recently receiving attention. In this method, no lead is used, and bonding can be achieved under temperature conditions lower than those for bulk silver. For example, in one method proposed under the above circumstances, a mixture of silver oxide particles and myristyl alcohol is used as a bonding material (Non Patent Literature 1 and Patent Literature 1). In another proposed method, carboxylic acid is added to a mixture of silver nanoparticles and silver carbonate or silver oxide, and the resultant mixture is used as a bonding material (Patent Literature 2).